#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=1e3+100;
typedef long long LL;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
LL x[maxn],y[maxn];

int main(void)
{
  cin.tie(0);std::ios::sync_with_stdio(false);
  LL t;cin>>t;
  while(t--){
    LL n;cin>>n;
    for(LL i=1;i<=n;i++){
        cin>>x[i]>>y[i];
    }
    LL k=(n+1)/2;
    LL ans=0;
    sort(x+1,x+1+n);
    sort(y+1,y+1+n);
    if(n&1) ans=1;
    else{
        ans=(x[k+1]-x[k]+1)*(y[k+1]-y[k]+1);
    }
    cout<<ans<<"\n";
  }
return 0;
}
